Compostable oxygen barrier comprising a biodegradable polymer matrix and biocarbon

Abstract

A biodegradable composite comprising a polymeric matrix including but not limited to poly lactide (PLA), poly (butylene succinate) 20 (PBS), poly(butylene succinate adipate) (PBSA), including bio-based PBSA (BioPBSA), poly(butylene adipate-co-terephthalate) (PBAT), polycaprolactone (PCL), polyhydroxyalkanoate (PHA(s)), poly(3-hydroxy)butyrate (PHB), poly(3-hydroxy-butyrate-hydroxyvalerate) (PHBV), copolyester of the monomers 1.4-butanediol, adipic acid and terephthalic acid (Ecoflex™) and polypropylene carbonate (PPC), and biocarbon, a.k.a. biochar or pyrolyzed biomass as a sustainable filler. The biodegradable composite achieves high oxygen barrier with balanced water barrier. Also, a method of manufacturing the biodegradable composite and articles of manufacturing comprising the biodegradable composite. The articles of manufacturing have application in limiting gas permeation into a package and extending shelf life of a material.

1 . A gas barrier substrate comprising a biodegradable composite, the biodegradable composite comprising a polymeric matrix and a sustainable filler comprising biocarbon, wherein the biodegradable composite has an oxygen transmission rate of 55 cc/m 2 -day or less, or an oxygen transmission rate of 20 cc/m 2 -day or less, or an oxygen transmission rate of 10 cc/m 2 -day or less, or an oxygen transmission rate of 2 cc/m 2 -day or less, or an oxygen transmission rate of 1 cc/m 2 -day or less, or an oxygen transmission rate of 0.2 cc/m 2 -day or less, wherein the oxygen transmission rate is calculated at normalized thickness of the biodegradable composite of 25.4 micrometer (1 mil) at 0% relative humidity, 23.7° C. 
     
     
         2 . The gas barrier substrate of  claim 1 , wherein the biodegradable composite has a water permeation rate of 300 g/m 2 -day, or less or has a water permeation rate of 150 g/m 2 -day or less, or a water permeation rate of 130 g/m 2 -day or less, or a water permeation rate of 125 g/m 2 -day or less or a water permeation rate of 10 g/m 2 -day or less, wherein the water permeation rate is calculated at normalized thickness of the biodegradable composite of 25.4 micrometer (1 mil) at 100% relative humidity, 37.8° C. 
     
     
         3 . The gas barrier substrate of  claim 1 , wherein the polymeric matrix comprises one or more biodegradable polymers. 
     
     
         4 . The gas barrier substrate of  claim 3 , wherein the polymer matrix comprises one or more of polylactide (PLA), poly(butylene succinate) (PBS), BioPBS (bio-based PBS), poly(butylene succinate adipate) (PBSA), BioPBSA (bio-based PBSA), poly(butylene adipate-co-terephthalate) (PBAT), polyhydroxyalkanoates (PHAs) including poly(3-hydroxy)butyrate (PHB) and poly(3-hydroxybutyrate-hydroxyvalerate) (PHBV), and a copolyester of 1.4-butanediol, adipic acid and terephthalic acid. 
     
     
         5 . The gas barrier substrate of  claim 4 , wherein the polymeric matrix comprises a binary blend of PBS/PBSA, PBS/PBAT, BioPBSA/the copolyester of 1.4-butanediol, adipic acid and terephthalic acid or PBSA/PBAT, or a ternary blend of PLA/PBS/PBAT, PHBV/BioPBSA/the copolyester of 1.4-butanediol, adipic acid and terephthalic acid or PBSA/PBAT/PHBV, or a quaternary blend of PLA/PBS/PBAT/PHBV or PLA/BioPBS/PBAT/PHBV. 
     
     
         6 . The gas barrier substrate of  claim 1 , wherein the polymeric matrix comprises PBS, PHBV or PLA as a major component of the polymeric matrix. 
     
     
         7 . The gas barrier substrate of  claim 1 , wherein the biodegradable composite is free of ethylene vinyl alcohol (EVOH) or polyvinyl alcohol (PVOH). 
     
     
         8 . The gas barrier substrate of  claim 1 , wherein the sustainable filler is a hybrid filler comprising (a) the biocarbon, and (b) a second filler selected from one or more of: starch; inorganic mineral fillers from talc or clay; and graphite or graphene. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . The gas barrier substrate of  claim 1 , wherein the biodegradable composite comprises up to 40 wt % of sustainable fillers. 
     
     
         12 . The gas barrier substrate of  claim 1 , wherein the gas barrier substrate is in the form of a pellet, a granule, an extruded solid, an injection molding solid, a hard foam, a sheet, a layer, a film, a dough or a melt. 
     
     
         13 . (canceled) 
     
     
         14 . The gas barrier substrate of  claim 1 , wherein the oxygen transmission rate of the gas barrier substrate is lower than the oxygen transmission rate of each one of PET, Nylon or EVOH. 
     
     
         15 . The gas barrier substrate of  claim 1 , wherein the biocarbon is one or more of pyrolyzed  miscanthus , pyrolyzed coffee chaff, pyrolyzed soy hull, pyrolyzed wood, pyrolyzed coffee ground or pyrolyzed oat hull. 
     
     
         16 . The gas barrier substrate of  claim 1 , wherein the biodegradable composite further comprises a compatibilizer from peroxide or maleic anhydride-grafted biopolymers. 
     
     
         17 . The gas barrier substrate of  claim 1 , wherein the gas barrier substrate is industrial compostable or home compostable. 
     
     
         18 . The gas barrier substrate of  claim 1 , wherein the gas barrier substrate is a single layer gas barrier. 
     
     
         19 . The gas barrier substrate of  claim 1 , wherein the gas barrier substrate is a multilayer gas barrier film, wherein at least one layer that forms the multilayer film exhibits gas barrier properties. 
     
     
         20 . An article of manufacture comprising the gas barrier substrate of  claim 1 . 
     
     
         21 . The article of manufacture of  claim 20 , wherein the article of manufacture is a packaging in shape of film, sheet, injection molded or thermoformed shapes. 
     
     
         22 . The article of manufacture of  claim 20 , wherein the article of manufacture is a packaging in shape of a coffee pod. 
     
     
         23 . A method of limiting gas permeation into an interior of a package, the method comprising at least partially or entirely covering the package with the article defined in  claim 20 . 
     
     
         24 . (canceled) 
     
     
         25 . A method of improving shelf life of a material which shelf life is reduced when exposed to a gas, the method comprising at least partially or entirely covering the material with the gas barrier substrate of  claim 1 . 
     
     
         26 . The method of  claim 25 , wherein the material is at least one of foods, pharmaceuticals, cosmetics, cement, and daily necessaries.